Method for preparing a drink and capsule for application of this method

ABSTRACT

A method for preparing a drink by passing hot water in a capsule ( 1 ), in which first at least one cut ( 10 ) extending in a linear fashion is made through the second wall ( 3 ) of the capsule ( 1 ), substantially without removing material from it. The adjacent portions ( 11 ) of the second wall ( 3 ) delimiting the cut ( 10 ) are then allowed to draw near one another again if necessary, then, by injecting hot water into the capsule, the internal pressure in the capsule is increased to cause at least partial expulsion of the air contained in it substantially without dispensing the liquid, and, then, by deformation of the second wall ( 3 ), the adjacent portions ( 11 ) delimiting the cut ( 10 ) are moved away from one another, allowing the drink to flow out. The invention also relates to an apparatus and a capsule for implementing this method.

DESCRIPTION

The present invention relates to a method for preparing a drink bypassing pressurised hot water in a sealed capsule, and to an apparatusand a capsule which allow this method to be implemented.

The present invention is intended in particular for preparing coffee,so, for the sake of simplicity, the following description refersexplicitly only to that drink. However, the present invention shallstill be considered as being intended for preparing any drink which canbe obtained by passing hot water in a capsule containing a substance tobe extracted or dissolved (normally grains or powder), according to themethods described below.

The use of disposable capsules for preparing coffee has been known formany years. They are usually sealed capsules, which may have filters,through which hot water, under pressure if necessary, is injected, toextract the coffee from the powder or grains contained in the capsule.The outflow of the drink is guaranteed by an opening made through thesecond wall of the capsule.

Since the quality of the drink obtained is very much dependent on themethods with which the water is passed through the capsule, with thepassage of time many processes and apparatuses intended for preparingsuch drinks have been developed. For example, a capsule containing amixture of powdered coffee can be used to obtain a simple infusion byslowly percolating low pressure hot water through it, or the so-called“espresso” (that is to say, a drink with significantly differentorganoleptic properties) if pressurised hot water is percolated throughit. The quality of the espresso may be further improved by forcedpre-infusion before starting to dispense the drink from the capsule,then maintaining a predetermined pressure in the capsule during theentire dispensing period.

Usually, the times, temperatures and pressures during the pre-infusionand dispensing steps, the intergranular flow speed and therefore themicro-turbulences generated are essential for obtaining a goodorganoleptic result. Since not all soluble substances contained incoffee are useful for an optimum result, attempts must be made tooptimise the extraction cycle so that the appearance, smell and tasteconfirm the positive outcome of the process. Up to now, these empiricalmeans have been the only ones considered really reliable to define thequality of the coffee.

Thus, the main technique for making a good quality espresso is broadlyspeaking widely known. However, in practice achieving a good level ofquality and maintaining it constant with the passage of time are notcertain and not easy. This is because there are many factors whichcontribute to the success of the operation, difficult to quantify andsometimes not even clearly identifiable, since even minimal changes inoperating circumstances may produce considerably different effects.Moreover, when selecting production methods, preference should be givento simple, reliable methods with low industrial cost, but whichguarantee a good end result. It is not commercially feasible to usemethods that are too complex and therefore too expensive in order toachieve an optimum result.

As already indicated, one of the techniques recognised as being able toimprove the result in terms of the quality of espresso coffee ispre-infusion. This consists of introducing hot water into the capsule,preventing it from flowing out until the internal pressure has reached apredetermined value (and if necessary this has been maintained for apredetermined time). This operation should allow the water to deeplypenetrate the micro-pores of the coffee granules/powder, thanks to itsown pressure compressing and therefore reducing the volume of thegaseous substances present in said pores. This deep penetration on onehand would allow the water to strike a significantly larger surface thanthat formed exclusively by the granule outer covering, and on the otherwould allow extraction of the aromas and essential oils found in thegranule which represent most of those possessed by the coffee.Therefore, in this way, a significantly improved coffee flavour andaroma could be extracted.

The fact that preparing drinks using capsules has been a matter of greatinterest for a long time is indicated by the many patents relating tothe subject. For example, the following: CH 406561, CH 605293, DE3722554, DE 7430109U, EP 199953, EP 211511, EP 242 556, EP 382001, EP468078, EP 468079, EP 468080, EP 469162, EP 471094, EP 507905, FR757358, FR 1198879, FR 1537031, FR 2062337, FR 2171306, FR 2556323, GB938617, GB 2023086, U.S. Pat. No. 2,715,868, U.S. Pat. No. 2,899,886,U.S. Pat. No. 3,094,917, U.S. Pat. No. 3,292,527, U.S. Pat. No.3,347,151, U.S. Pat. No. 3,403,617, U.S. Pat. No. 3,470,812, U.S. Pat.No. 3,589,272, U.S. Pat. No. 4,077,551, U.S. Pat. No. 4,136,202, U.S.Pat. No. 4,921,712 and WO 86/02537.

Further examples of patents describing various methods for opening thecapsules are the following: WO 2005090196, EP 1557373, EP 1243210, EP1674007, EP 0726053, EP 1599117, WO 9507648, U.S. Pat. No. 5,243,164, EP1555218, EP 1247756.

Said patent documents substantially describe three main methods forpreparing coffee or drinks using disposable sealed capsules: a firstmethod in which the second wall of the capsule is pierced before wateris injected into it, which therefore does not use pre-infusion; a secondmethod making use of the inward opening of an openable portion of thebase of the capsule (patents EP 1557373 and EP 1243210); and a thirdmethod, which instead uses pre-infusion, and in which the second wall ofthe capsule is pierced as a direct consequence of the increase ininternal pressure due to injecting water into it.

Relative to the second method, patent EP 1243210 and patent EP 1557373describe two very similar solutions in which the capsule opens by meansof an inward deformation of an openable part of the base wall. In thecase of patent EP 1557373, the openable part is obtained by pushing inthe base wall along a weakening line using an external punch after theinternal pressure has reached a predetermined value. In contrast, in thecase of patent EP 1243210, the capsule is already made with the openablepart, although the latter is shaped in such a way as to form a valve atthe start of water injection into the capsule. In particular, theopenable part rests on the remaining part of the base so that it cannotopen outwards. Consequently, the base is actually opened by means of anouter contact element which interacts with the openable part when,following the increase in pressure, the capsule is sufficiently swollen.In contrast, the third above-mentioned method has two main forms.

The first form, described for example in patent U.S. Pat. No. 4,136,202,involves the cartridge splitting open due to the increase in pressure,preferably at its weakened zones.

In the second form, coffee dispensing begins after the base of thecapsule has been pierced due to the base swelling as a result of theinternal pressure generated by the entry of the water, meaning that thebase is torn against a fixed element which is integral with and projectsfrom the base of the capsule housing body (patents EP 468 078 and EP 507905). The tear obtained in this way allows the air and liquid to flowout at a pressure which depends on the resistance to piercing of thebase of the capsule and the shape of the projecting sharp element.

However, these prior art technical solutions have several disadvantages.When the base of the capsule is pushed in, a condition producing theabove-mentioned compression of the air or gas in the coffee granulemicro-pores has not been achieved. The increase in pressure occurs withthe simultaneous presence of liquid and air/gas in the entire capsuleand not just in the micro-pores, meaning that practically only the airoutside the micro-pores is compressed. As a result, the water does notpenetrate the micro-pores unless there are marginal phenomena such asmicro-turbulences which can dynamically remove part of the air containedin some of these micro-pores.

However, it should be noticed that during the drink dispensing step, dueto the dynamic resistance to drink outflow from the hole, there is acertain new increase in the capsule internal pressure, which can allowthe water to partly penetrate the coffee granule micro-pores. On theother hand, following said new increase, in the absence of the reductionin pressure which would be necessary for the liquid penetrated to flowout, the solubilised substances only partly flow out of the granule.

Thus, the prior art, although allowing results in which the quality ofthe drink is sometimes good, implement substantially inefficientpre-infusion treatments, and therefore are susceptible of further,significant improvements. They are also not without constructionproblems, including in particular the narrowness of the componentstolerances necessary to guarantee tearing of the base walls of thecapsules in the required times and ways, with the necessaryrepeatability and constancy with the passage of time.

It is necessary to work very close to the maximum limits of capsuleresistance to piercing in order to obtain satisfactory results, whichmakes it difficult to optimise the set of various parameters andtolerances involved (maximum pressure which can be reached by the pump,deformability of the capsule material and relative thickness, nature ofthe compound, ambient temperature, incisiveness of the piercing element,degree of projection of the latter and size tolerances in general).

From all of this it is possible to infer that there is a risk of earlypiercing or even no piercing at all. Moreover, perforation may sometimesbe too resolute, leaving open a hole which does not sufficiently opposethe outflow, or the hole may have difficulty opening, lengthening thedispensing time more than necessary.

As already indicated, other known methods mechanically pierce the baseof the capsule (in some cases removing portions, in others plasticallydeforming the edges delimiting the hole) before or simultaneously withthe start of water entering the capsule. For simple construction, thosemethods do not use pre-infusion, instead seeking an acceptable result inother ways: high operating pressure values, very fine size of the grainsground, high operating temperatures, reduced hydraulic flow rates,turbulence phenomena induced by special capsule internal shapes. All ofthese methods are partly suitable for the purpose but are in turncomplex and not very reliable (without unacceptable increases inproduction costs). Other methods use electronic control devices,obtaining a very moderate pre-infusion at atmospheric pressure and thenraise the pressure during the subsequent step, increasing the pumpcapacity.

In short, all of these prior art methods obtain results which areuncertain or not entirely satisfactory, often with considerably highcosts.

In this situation the technical purpose which forms the basis of thepresent invention is to provide a method for preparing a drink whichovercomes the above-mentioned disadvantages, as well as providing anapparatus and a capsule which allow this method to be implemented. Inparticular the technical purpose of the present invention is to providea method for preparing a drink and a relative capsule and apparatus ableto allow the preparation of drinks with optimum organoleptic properties.

Another technical purpose of the present invention is to provide amethod for preparing a drink and a relative capsule and apparatus whichguarantee a result which can be repeated and remains constant with thepassage of time.

The technical purpose specified and the aims indicated are substantiallyachieved by a method for preparing a drink, the relative apparatus andcapsule as described in the claims herein. Further features andadvantages of the present invention are more apparent in the detaileddescription below, with reference to several preferred, non-limitingembodiments of a method for preparing a drink and the relative apparatusand capsule, illustrated in the accompanying drawings, in which:

FIG. 1 is a partial schematic side view of an apparatus made inaccordance with the present invention;

FIG. 2 is a side section of the apparatus of FIG. 1;

FIG. 3 is a schematic view of a capsule and capsule cutting means inaccordance with the present invention;

FIG. 4 shows the capsule and the cutting means of FIG. 3 according tothe line IV-IV;

FIGS. 5 to 7 are schematic illustrations of several steps of the methodin accordance with the present invention; and

FIG. 8 shows an alternative embodiment of movement means of theapparatus according to the present invention.

The method for preparing a drink in accordance with the presentinvention involves the use of a capsule 1 (for example of the typeillustrated in FIGS. 3 and 4) having a first wall 2 and a second wall 3connected by a lateral wall 4 and which contains a substance 5 to beextracted such as coffee powder or grains. Advantageously, the capsule 1may also contain filters or diffusers 6 of the type illustrated in FIG.4. Moreover, in the embodiment illustrated in the accompanying drawings,the first wall 2 is the upper wall of the capsule, whilst the secondwall 3 is the lower wall of the capsule.

In the known way, the method for preparing the drink comprises theoperating steps of creating a first opening through the first wall 2 ofthe capsule 1, creating a second opening 7 through the second wall 3 ofthe capsule 1, injecting hot water into the capsule 1 through the firstopening and making the drink flow out through the second opening 7.

The first opening may be created in any way, for example using a spike 8integral with a movable part of the apparatus 9, as illustrated in theaccompanying drawings and described below.

Similarly, the water can be injected into the capsule 1 in any way, forexample using channels directly or indirectly associated with the spike8 which pierces the first wall 2. In turn, according to the presentinvention, the step of creating the second opening 7 through with thedrink must be able to flow out, comprises a plurality of steps. First,there is an operating step in which at least one cut 10 extending in alinear fashion is made through the second wall 3 of the capsule 1. Saidcut 10, preferably made before the injection step, is advantageouslysubstantially made without removing material from the capsule 1 wall, sothat it is delimited by two adjacent portions 11 of the second wall 3.The cut 10 is preferably obtained using a blade 12. Moreover, it may bemade both extending in a straight fashion, and extending in a curvedfashion, although it is preferably made in such a way that it does notdelimit lobed portions, that is to say, so that the distance between twonon-adjacent points of the cut 10 is always greater than the reciprocaldistance between all of the points in between the first two.

In addition, the step for creating the cut 10 is preferably carried outwithout affecting what is contained in the capsule 1 (in particular, thefilter 6 which may separate the base of the capsule from the coffeepowder). Finally, in the most common embodiments, the cut 10 is normallymade so that it has a length of between 2 and 6 mm.

Depending on requirements, a plurality of cuts 10 may be made, eachdelimited by two adjacent portions 11 of the capsule 1 base, cuts 10which may each be in a different zone of the second wall 3, or mayintersect.

It should also be emphasised that the step of making the cut 10 may becarried out at a different moment to that of preparing the drink. Thecut may already be made at the moment the capsule 1 is produced. In sucha case, however, the cut 10 is preferably covered to preserve theorganoleptic properties of the substance contained in the capsule. Forexample, each capsule may be individually packaged in a hermeticallysealed wrapper, or the cut may be covered with an adhesive protectivefilm which must be removed before using the capsule.

After the cut 10 has been made, there follows a step during which theadjacent portions 11 of the second wall 3, which delimit the cut 10, maydraw near one another again, to substantially prevent, directly orindirectly, as described below, the drink from flowing out through thecut. This entails, firstly, removal if necessary, from the cut 10, ofthe cutting means 35 used (blade 12 or other). Only at this point arethe adjacent portions 11 which delimit the cut 10 free to draw near oneanother again, if necessary returning to their starting position. Inparticular, when the operating to create the cut 10 has moved (byelastic deformation) the adjacent portions 11 from their originalposition (typically a movement towards the inside of the capsule 1), theactual drawing near again of the adjacent portions may take place bothbefore the subsequent injection step (for example thanks to theelasticity of the adjacent portions 11) or after the injection step dueto the increase in pressure generated inside the capsule 1. Moreover,the expulsion of the cutting means 35 from the cut 10 may be caused bythe increase in pressure inside the capsule 1 due to the injection step.

In any event, according to the present invention the step of drawingnear again is performed in such a way that after said step the cut 10has a transversal size and/or a shape such that it substantiallyprevents the passage of liquid through it, but it does allow the passageof air. As described below, in this way the cut 10 allows air to beemptied out of the capsule 1 and, at the same time, optimum pre-infusionof the drink. If this were not possible, after the step of drawing nearagain the cut 10 would still preferably have a transversal size and/or ashape such that it substantially prevents the passage through it ofparticles of the substance 5 to be extracted (coffee) which are normallyremoved by the first drops of water passing through the substance.Therefore, in this case, another operating step may be identified, ofblocking the cut 10 by means of said particles carried close to the cut10 by the water injected into the capsule 1. As may easily be inferred,during this blocking step some drops of liquid exit the second opening 7until the latter is completely blocked. However, in this case it is notpossible to refer to drink dispensing.

Therefore, when the cut 10 is made in such a way that it has atransversal size such that it satisfies one of the two above-mentionedrequirements, following injection of the water into the capsule 1 atleast part of the air contained in it is expelled, after which severaldrops of liquid may be dispensed, but this is followed by a period inwhich drink dispensing is substantially inhibited.

In other words, at the moment when the water enters the capsule 1, thecut 10 made through the second wall 3 acts as a valve, practically openfor the air or the gases contained in the capsule 1 but closed for thevery first drops of liquid arriving which are dense with solidparticles.

This is also the case when the transversal size of the cut 10 is toosmall to allow the passage of air. In that case, the edges delimitingthe cut 10 are substantially coplanar and butted together but withoutbeing integral with one another. However, a minimal overpressure in thecapsule 1 (for example around 0.1 bar) is sufficient for the two edgesdelimiting the cut 10 to move away from one another, bending slightly insuch a way as to create a gap sufficient for the passage of a gas.However, in this patent, said minimal bending is not considered adeformation of the second wall 3, since that definition is reserved fordeformations which allow the passage of the drink.

As already indicated, at this point of the method disclosed, the drinkis still unable to exit the capsule 1, since the second opening 7 canstill not be considered completely formed. Consequently, in thesubsequent step of the method disclosed, after the above-mentioned airexpulsion, by continuing the step of injecting hot water into thecapsule 1, the internal pressure in the capsule 1 is further increasedto produce a substantial deformation (elastic or permanent) of thesecond wall 3, and a consequent movement away from one another of theadjacent portions 11 delimiting the cut 10, so that the drink can pass.Moreover, depending on requirements, the deformation of the second wall3 may affect only part of the second wall (as in the case of theapparatus illustrated in the accompanying drawings), or the whole of thesecond wall 3.

Therefore, advantageously the injection step is in turn divided into afirst sub-step during which the internal pressure in the capsule 1increases without deforming the second wall 3 but expelling the air, anda second sub-step during which the pressure is further increased andinstead deforms the second wall 3 (advantageously an elasticdeformation). In practice, the passage from the first to the secondsub-step corresponds with exceeding a threshold pressure to overcome thestructural resistance of the second wall 3 of the capsule 1 and/or allowthe expulsion of any particles blocking the cut 10.

It is immediately clear that the force necessary for the step ofsubstantially deforming the second wall 3 must be much greater than thatneeded to allow the edges to move away from one another so that the aircan flow out if the cut 10 has a very limited transversal size. Thiscircumstance is accentuated by the fact that the microscopic particlesaccumulated at the cut 10 have a blocking action on the 10 which helpsto keep it substantially hermetically sealed, preventing the passage ofliquid through it. It should be noticed that, approximately andschematically, it is possible to imagine the micro-particles having aspherical shape with an average diameter of around 0.1-0.2 mm, so that,to allow them to pass through the cut 10 and consequently unblock thecut 10 and allow the liquid to flow out, the deformation required ismuch greater than that sufficient to allow the passage of air or liquidonly. From this it may be inferred that the pressure must risesignificantly before the cut 10 actually opens and allows the passage ofthe drink. Approximately, the overpressure must be at least 20-30 timesthat which allows the simple passage of air. However, it should benoticed that all of the values supplied here are given by way of exampleonly and in no way limit the scope of the invention, since in practicethey are inseparably linked to the shape and size of the cut 10 and tothe thickness and type of the material used to make the second wall 3 ofthe capsule 1.

FIGS. 5 to 7 schematically illustrate the steps of making the cut 10,drawing near again of the adjacent portions delimiting the cut andsubsequent deformation of the second wall 3 of a capsule 1.

It should also be noticed that, if two or more cuts are made through thesecond wall 3, all of the steps described above, and in particular thatof drawing near again and moving away of the adjacent portions 11 whichdelimit them, are preferably carried out for each cut 10.

As regards production of the drink, it should be noticed that in thestep of increasing the pressure and expelling the air, with the cut 10still closed, there is a deep and extensive penetration of the liquid inthe micro-cavities of the granules, which allows abundant extraction ofthe desired organoleptic substances, and which is made possible by thefact that the air and/or gases in the intergranular spaces are graduallyexpelled. Therefore, at the end of expulsion, the only air/gas remainingis that in the micro-pores of the individual granules, which istherefore easy to compress and its volume can be reduced by up to 5-10times. However, the actual compression of said air depends on theinternal pressure in the capsule 1, so that maximum compression isachieved at the moment when deformation of the second wall 3 and/orexpulsion of the blocking particles allow the drink to flow out of thecut 10 (maximum pressure moment).

Immediately after the start of drink dispensing there is a rapidreduction in the internal pressure in the capsule 1, which allows theair/gas in the micro-pores to expand again, pushing out the water whichpreviously penetrated there and which in the meantime extracted thearomas from inside the particles. The swiftness of the phenomenon alsocauses micro-turbulence phenomena very useful to the extraction process.

The method described above may be implemented with any apparatus 9suitable for the purpose.

However, a preferred embodiment of an apparatus 9 for implementing themethod described above is described below with reference to FIGS. 1 to4.

In general, the apparatus 9 comprises at least one housing 13 in which acapsule 1 containing the substance 5 to be extracted can be inserted,and associated with means 14 for creating a first opening through afirst wall 2 of the capsule 1 and means 15 for creating a second opening7 through a second wall 3 of the capsule 1. Advantageously, the housing13 is shaped to match the capsule 1 which must be inserted in it.

In the embodiment illustrated, the apparatus 9 also comprises a mainbody 16 and a secondary body 17 which operate in conjunction with oneanother to form the housing 13. Whilst the volume of the housing 13 isalmost completely inside the main body 16, the secondary body 17 ismovable relative to the main body 16 between an open position in whichit allows access to the housing 13, and a closed position in which ithermetically seals the housing 13 and forms its upper closing wall.

In particular, the housing 13 is mostly made in the upper face of themain body 16, whilst the secondary body 17 is positioned above the upperface and pivots at the main body 16 according to a horizontal axis ofrotation 18. The secondary body 17 may therefore rotate between theclosed position (in which it is horizontal in the accompanying drawings)and the open position (in which it is rotated upwards relative to theclosed position). In FIGS. 1 and 2 the secondary body 17 is shown in anintermediate position between the open and closed positions.

Sealing means 19, in the accompanying drawings shown as a ring-shapedseal, are inserted between the main body 16 and the secondary body 17,being designed to create a seal between the capsule 1 and the secondarybody 17.

There is also at least one discharge pipe, not illustrated, which in theknown way allows the drink to flow out of the housing 13.

The reciprocal movement of the main body 16 and the secondary body 17 isguaranteed by means 20 for moving the secondary body 17 relative to themain body 16.

In the embodiment illustrated in FIG. 1, the movement means 20 comprise:

-   -   at least one first rocker arm 21 whose intermediate portion        pivots at the main body 16; at least one actuator element 22        associated with a first end 23 of the first rocker arm 21; and    -   at least one bar 24 whose first end 25 pivots at a second end 26        of the first rocker arm 21, and whose second end 27 pivots at        the secondary body 17.

Advantageously, however, the apparatus 9 comprises two first rocker arms21 and two bars 24 mounted specularly on the two sides of the main body16, whilst the actuator element 22 is associated with both of the firstrocker arms 21. The actuator element 22 may for example consist of aC-shaped element in which the two arms of the C are connected to the twofirst rocker arms 21 whilst the central part forms a handgrip for a user(not illustrated).

Rotation of the first rocker arm 21 about the point where it pivots atthe main body 16 using the actuator element 22, causes by means of thebar 24, rotation of the secondary body 17 between the open position andthe closed position.

In the embodiment illustrated in FIG. 1, the first rocker arm 21 has acurved shape (substantially forming a right angle) and the actuatorelement 22 is connected to the rocker arm according to a direction ofaction X substantially parallel with the line joining the point 28 wherethe first rocker arm 21 pivots at the main body 16 to the point 29 wherethe bar 24 pivots at the first rocker arm 21 (FIG. 1).

Each first rocker arm 21 can move between a maximum traction position inwhich the point 29 where the bar 24 pivots at the first rocker arm 21 isvertically aligned below the point 28 where the first rocker arm 21pivots at the main body 16, and a position in which the housing 13 isopen (positions not illustrated in the accompanying drawings).

When the first rocker arm 21 is in the open position, the point 29 wherethe bar 24 pivots at the first rocker arm 21 is rotated through apredetermined angle of rotation relative to the maximum tractionposition, according to a second direction of rotation which in FIG. 1 isclockwise. In the first rocker arm 21 maximum traction position, thesecondary body 17 is in its position closest to the main body 16, andtherefore with maximum pressing of the sealing means 19. However, toprevent housing 13 accidental opening, the apparatus 9 also comprisesmeans 30 for locking the bar 24 when the secondary body 17 is in theclosed position, said means comprising at least one tooth 31 and atleast one cavity 32 shaped to match the tooth, one associated with thebar 24 and the other associated with the main body 16 (two in FIG. 1).FIG. 8 shows an alternative embodiment of the movement means 20. Theportion of the first rocker arm 21 forming the first end 23 issubstituted by a first ring gear 50 concentric to the point 28 where thefirst rocker arm 21 pivots at the main body 16. The first ring gear 50meshes with a second ring gear 51 pivoting at the main body 16 by meansof a pin 52. The second ring gear 51 may be rotatably driven about thepin 52 by an actuator element 22 which may be rigidly connected eitherdirectly to the second ring gear 51 or to a through-bar (notillustrated) which joins two first ring gears 51 positioned on the twosides of the main body 16 (similarly to what is described above relativeto the first rocker arms 21). Therefore, in this case the actuatorelement 22 is not rigidly constrained to the first rocker arm 21 butonly engages with it. Associated with the housing 13 there are means forinjecting hot water into the capsule 1, which in the embodimentillustrated comprise a channel 33 terminating in a recess 34 extendingaround the means 14 for creating the first opening which in turn consistof a fixed spike 8 integral with the secondary body 17 and positioned insuch a way that it projects into the housing 13, piercing the capsule 1when the housing 13 is closed.

In any case, the means for injecting water and creating the firstopening may take any form (for example the channel 33 may extend intothe spike 8 which may be made hollow).

The heart of the apparatus 9 disclosed consists of the fact that themeans 15 for creating the second opening 7 comprise cutting means 35designed to make at least one linear cut 10 through the second wall 3,as well as the fact that it also comprises movement means 36 forreciprocally moving the cutting means 35 and the housing 13 between acutting position in which the cutting means 35 project into the housing13 and can cut the second wall 3 of a capsule 1 inserted in it, and ahome position in which the cutting means 35 cannot interfere with acapsule 1 inserted in the housing 13. As shown in FIG. 2, in the caseillustrated the main body 16 and therefore the housing 13 remainstationary, whilst the movement means 36 only act on the cutting means35.

In the embodiment illustrated, the cutting means 35 comprise at leastone blade 12 integral with an upper end of a rod 37 which can movevertically below the housing 13 between a lower position and an upperposition. The thickness of the blade 12 is preferably limited, so thatthe cut 10 it produces is a substantially linear cut 10 (straight orcurved) in accordance with the present invention. The rod 37 is slidablymounted with a hydraulic seal through the main body 16.

The movement means 36 move the rod 37 is such a way that when it is inthe upper position the blade 12 projects into the housing 13, and whenit is in the lower position the blade 12 is inserted in a recess 38 madeat the base of the housing 13. The recess 38 may also have the functionof delimiting the zone of the second wall 3 which may be deformed. Ifthe base of the housing 13 is shaped to match the second wall 3, onlythe portion of the second wall 3 at the recess 38 may be subject to thedeformation step described above.

In the embodiment illustrated the movement means 36 comprise at leastone second rocker arm 39 with an intermediate portion pivoting at themain body 16 and connected at a first end 40 to the cutting means 35 (tothe rod 37) and at a second end 41 to an actuator element 42. In thisway, the second rocker arm 39 can move between a first position in whichthe cutting means 35 are in the home position (FIG. 2) and a secondposition in which the cutting means 35 are in the cutting position (notillustrated).

Advantageously, an elastic return element (spring) 43 is connected tothe second rocker arm 39 so that, in the absence of stresses from theactuator element 42, it is held in its first position. In FIG. 2, theelastic element 43 is connected between the second rocker arm 39 and theactuator element 42. Upward movement by the latter is prevented by avertical projection 44 of the main body 16 which also has anotherfunction described below.

Moreover, in the preferred embodiment the means 36 for moving thecutting means 35 are operated directly by the movement means 20 of thesecondary body 17. For this purpose, the actuator element 42 has a firstengagement element 45 which can engage with the movement means 20, andin particular with a second engagement element 46 integral with thefirst rocker arm 21, to move the actuator element 42 when the main body16 moves from the open position towards the closed position, so as tomove the cutting means 35 towards the cutting position. In particular,when the secondary body 17 is close to the closed position, the secondengagement element 46 hooks to the first engagement element 45 so thatthe further rotation of the first rocker arm 21 (anticlockwise in FIG.2) causes a rotation—translation of the actuator element 42 (with amovement to the right in FIG. 2) and, consequently a rotation of thesecond rocker arm 39 (anti-clockwise in FIG. 2) which causes the cuttingmeans 35 to be lifted towards the cutting position. Since the secondarybody 17 is close to the closed position, the capsule 1 is practicallylocked in the housing 13 and its second wall 3 can easily be cut by thecutting means 35.

Once the cut 10 has been made, a further rotation of the first rockerarm 21 causes the first engagement element 45 to interact with the rigidprojection 44 integral with the main body 16 which constitutes adisengagement element. Partly thanks to the sloping shape of the firstengagement element 45, its interaction with the projection 44 causes itto rotate downwards, resulting in the first engagement element 45 beingreleased from the second engagement element 46. At this point, theelastic return element 43 returns both the second rocker arm 39 and theactuator element 42 to the original position illustrated in FIG. 2,extracting the cutting means 35 from the housing 13. Finally, it shouldbe noticed that the various parts are sized in such a way to disengagethe actuator element 42 from the first rocker arm 21 before thesecondary body 17 has reached its closed position.

Finally, as already indicated, the present invention also relates to acapsule for preparing drinks which allows the implementation of themethod described above.

In the known way, the capsule contains a substance to be extracted andcomprises at least a first wall 2 designed to form an inlet wall for thewater to be injected into the capsule, and a second wall 3 designed toform an outlet wall for a drink obtained by interaction between thewater and the substance to be extracted.

In accordance with the present invention, the second wall 3 has at leastone cut 10 extending in a linear fashion, substantially made withoutremoving material from the second wall 3. The cut is delimited by twoadjacent portions 11 of the second wall drawn near one another, and hasa size and/or shape such that, after the adjacent portions 11 delimitingit (of the type described above) have drawn near one another again ifnecessary, it allows the passage of air and substantially, directly orindirectly, prevents the passage of liquid.

In particular, the cut 10 has a size and/or shape such that, after theadjacent portions 11 delimiting it have drawn near one another again ifnecessary, it substantially prevents the passage of particles of thesubstance contained in the capsule 1 which the water carries to it, theparticles and the cut 10 operating in conjunction with one another toprevent the passage of liquid.

As already indicated, the cut 10 may have a length of between 2 and 6mm.

Moreover, the capsule may have a plurality of cuts 10, each delimited bytwo adjacent portions 11 drawn near one another, which may each be in adifferent zone of the second wall 3, or may intersect.

The capsule made as described above corresponds to the embodiment of themethod disclosed in which the cut 10 through the second wall is made atthe moment when the capsule is produced.

The present invention brings important advantages.

Firstly, the method disclosed allows a reliable and constantpre-infusion without the need for narrow tolerances or particularlycomplex and expensive mechanical, electromechanical or electronic parts.

Moreover, it is not subject to jamming by the coffee particles. In theevent of jamming, the pressure in the capsule would rapidly increaseagain, automatically expelling the blockage. However, it should beemphasised that in practice it has been demonstrated that the blockagephenomenon is normally only manifested with the first drops of drinksdense with particles. The apparatus has the great advantage that with asingle operating movement it is possible to control all of theoperations linked to making the cut and closing/opening the housing.

Moreover, the method for closing the housing through interaction betweenthe teeth and the cavities guarantees the maximum capacity forabsorption of the stresses deriving from the internal pressure.

It should also be noticed that the present invention is relatively easyto produce and even the cost linked to implementation of the inventionis not very high.

The invention described may be modified and adapted in several wayswithout thereby departing from the scope of the inventive concept.

All details of the invention may be substituted by technicallyequivalent elements and, in practice, all of the materials used, as wellas the shapes and dimensions of the various components, may be anyaccording to requirements.

The invention claimed is:
 1. A method for preparing a drink by passinghot water in a capsule (1) which has a first wall (2) and an unpiercedsecond wall (3) and which contains a substance (5) to be extracted, themethod being implemented by an apparatus for preparing a drink andcomprising the operating steps of: creating a first opening through thefirst wall (2) of the capsule (1); creating a second opening (7) throughthe second wall (3) of the capsule (1); injecting hot water into thecapsule (1) through the first opening; and making the drink flow outthrough the second opening (7); the method being characterised in thatthe step of creating the second opening (7) in turn comprises theoperating steps of: making at least one cut (10) extending in a linearfashion through the second wall (3) of the capsule (1), substantiallywithout removing material from the second wall (3), said cut (10) beingdelimited by two adjacent portions (11) of the second wall (3), the cut(10) being made using cutting means (35); removing the cutting means(35) from the cut (10) and allowing the adjacent portions (11) of thesecond wall (3), which delimit the cut (10), to draw near one anotheragain; and after said drawing near again and by means of said injectionof hot water, increasing the internal pressure in the capsule (1) tocause, in succession: at least partial expulsion of the air contained inthe capsule without substantial dispensing of the drink; and by means ofan outward deformation of the second wall (3) at least at said adjacentportions (11), a movement away from one another by the adjacent portions(11) delimiting the cut (10), allowing the drink to flow out.
 2. Themethod according to claim 1, characterised in that the step of theadjacent portions (11) drawing near one another again occurs before saidinjection step.
 3. The method according to claim 1, characterised inthat the step of the adjacent portions (11) drawing near one anotheragain involves their drawing near one another again being caused by saidinjection step.
 4. The method according to claim 1, characterised inthat the step of the adjacent portions drawing near one another again iscarried out in such a way that, following said step, the cut (10) has asize and/or shape such that it allows the passage of air.
 5. The methodaccording to claim 4, characterised in that the step of the adjacentportions drawing near one another again is carried out in such a waythat, following said step, the cut (10) has a size and/or shape suchthat it substantially prevents the passage of liquid.
 6. The methodaccording to claim 4, characterised in that the step of the adjacentportions drawing near one another again is carried out in such a waythat, following said step, the cut (10) has a size and/or shape suchthat it substantially prevents the passage of particles of the substance(5) to be extracted which are carried to the cut (10) by the waterinjected into the capsule (1), the passage of liquid through the cut(10) in this way being prevented by the cut (10) operating inconjunction with the particles of the substance (5) accumulated at thecut.
 7. The method according to claim 6, characterised in that it alsocomprises a step of blocking the cut (10) using particles of thesubstance (5) to be extracted carried to the cut (10) by the waterinjected into the capsule (1).
 8. The method according to claim 7,characterised in that the blocking step takes place at the start of theinjection step, before deformation of the second wall (3) allows drinkdispensing.
 9. The method according to claim 8, characterised in that,during the step of deformation of the second wall (3), there is also astep of expulsion of the particles.
 10. The method according to claim 1,characterised in that the injection step is divided into a firstsub-step during which the internal pressure in the capsule (1)substantially increases without deformation of the second wall (3) andwithout drink dispensing, and into a second sub-step during which thepressure is further increased and causes the deformation of the secondwall (3) and consequent drink dispensing.
 11. The method according toclaim 1, characterised in that the step of deformation of the secondwall (3) involves an elastic or permanent deformation of the wall. 12.The method according to claim 1, characterised in that the step ofmaking at least one cut (10) involves making the cut (10) so that itextends in a straight fashion.
 13. The method according to claim 1,characterised in that the step of making at least one cut (10) involvesmaking the cut (10) so that it extends in a curved fashion.
 14. Themethod according to claim 1, characterised in that the step of makingthe cut (10) is carried out without affecting what is contained in thecapsule (1).
 15. The method according to claim 1, characterised in thatthe cut (10) is made with a length of between 2 and 6 mm.
 16. The methodaccording to claim 1, characterised in that during the step of makingthe cut (10) a plurality of cuts are made, each delimited by twoadjacent portions (11), and in that it comprises, for each cut (10) saidsteps of the adjacent portions (11) delimiting the cut drawing near oneanother again and moving away from one another.
 17. The method accordingto claim 16, characterised in that said cuts are made in such a way thateach is in a different zone of the second wall (3).
 18. The methodaccording to claim 16, characterised in that at least some of said cutsintersect.
 19. The method according to claim 1, characterised in thatthe step of deformation of the second wall (3) involves only part of thesecond wall (3) at the cut (10).
 20. The method according to claim 1,characterised in that the step of deformation of the second wall (3)involves the entire second wall (3).